Control System for Working Machine

ABSTRACT

A plurality of control units capable of communicating with each other via a data communication network (TU) are disposed in distribution. One of the plurality of control units is set as an information management control unit (H 1 ) having writable nonvolatile storing means. Upon activation with power supply thereof, the information management control unit (H 1 ) executes a control management information distributing process for transmitting control management information stored in a memory ( 50 ) to storage object control units (H 2 -H 6 ) via the communication network (TU). Upon activation with power supply thereto, each of the storage object control units (H 2 -H 6 ) executes a control management information obtaining process for obtaining the control management information transmitted from the control management information control unit (HI).

TECHNICAL FIELD

The present invention relates to a control system for a working machinecomprising: a plurality of control units disposed in distribution to becapable of communicating with each other via a data communicationnetwork, each one of the plurality of control units controlling acontrolled object assigned thereto, based upon input informationinputted by information inputting means included in this unit, controlinformation communicated from a further control unit, and controlmanagement information.

BACKGROUND ART

With the above-described control system for a working machine, each oneof the plurality of control units controls a controlled object assignedthereto. Various kinds of information such as the input informationinputted by the information inputting means provided in one control unitand information indicative of a control condition of the controlledobject can be utilized for controlling in a further control unit. And,such information is transmitted as the control information from the onecontrol unit to the further control unit via the data communicationnetwork. Further, when the control unit controls the controlled objectassigned thereto, the unit uses the control management information. Asone example of this control management information, the following datacan be cited. That is, a control unit having an actuator as thecontrolled body capable of moving an operated object and a potentiometertype detecting sensor for detecting an operational position of theoperated object uses fine adjustment data for adjusting individualdifference in the detection values of the detecting sensor when thecontrolled body operated by the actuator is operated to a referenceposition. These fine adjustment data represent an example of the abovedata.

As a conventional example of such control system for a working machine,from JP-A-2005-059773 (Patent Document 1), there is known a systemwherein each one of the plurality of control units includes a writablenonvolatile memory (EEPROM) for storing the control managementinformation for use in each control unit.

The control management data such as the fine adjustment data describedabove are generally determined in advance and stored in the memory,prior to shipment of the working machine from the manufacturing factory.And, if a trouble develops in the detecting sensor or the actuator withuse of the working machine, a maintenance operation is effected on thissensor or actuator. In this case too, determination of data and writingthereof into the memory are to be effected again. Therefore, in order toallow rewriting of the control management information and also to avoidinadvertent deletion of the stored information upon stop of powersupply, the control management information is stored in the writablenonvolatile memory.

According to the above-described conventional technique, each one of theplurality of control units is equipped with the writable nonvolatilememory for storing the control management information, through which thecontrol unit can control the assigned controlled object appropriately.However, since each one of the plurality of control units is equippedwith the memory as described above, a large number of writablenonvolatile memories are required.

Patent Document 1: Japanese Patent Application “Kokai” No. 2005-059773(JP-A-2005-059773).

DISCLOSURE OF INVENTION

The object of the present invention is to provide a control system whichnot only allows each one of the plurality of control units to control acontrolled object assigned thereto appropriately, but allowssimplification and cost reduction of the system through reduction in thenumber of writable nonvolatile memories.

The above object is fulfilled, according to one aspect of the inventionas under:-

A control system for a working machine comprising: a plurality ofcontrol units disposed in distribution to be capable of communicatingwith each other via a data communication network, each one of theplurality of control units controlling a controlled object assignedthereto, based upon input information inputted by information inputtingmeans included in this unit, control information communicated from afurther control unit, and control management information;

wherein said plurality of control units are composed of an informationmanagement control unit and storage object control units separate fromthe information management control unit, the information managementcontrol unit having a writable nonvolatile memory for storing thecontrol management information of the storage object control units aswell as the control management information of this the informationmanagement control unit;

upon activation by power supply thereto, said information managementcontrol unit executes a control management information distributingprocess for transmitting the control management information stored inthe memory to said storage object control units via the datacommunication network; and

upon activation by power supply thereto, each one of said storage objectcontrol units executes a control management information obtainingprocess for receiving the control management information for its owntransmitted from said information management control unit via said datacommunication network.

That is to say, any one of the plurality of control units is set as theinformation management control unit and includes a writable nonvolatilememory for storing the control management information. And, this memorystores therein control management information for its own, i.e. for thisinformation management control unit, as well as the control managementinformation for all or some of the other control units of the pluralityof control units other than the information management control unit,i.e. for the storage object control units.

And, upon activation with supply thereto, the information managementcontrol unit transmits the control management information stored in thememory thereof to the storage object control units, so that each one ofthese storage object control units, upon activation with power supplythereto, receives the control management information for its own,transmitted from the information management control unit via the datacommunication network.

That is to say, the control management information of the plurality ofcontrol units as the storage object control units, can be stored in thewritable nonvolatile memory included in one of the plurality of controlunits. So, there is no need to provide the writable nonvolatile memoryin each and every one of the plurality of control units. Hence, for thesystem as a whole, the number of writable nonvolatile memories can bereduced correspondingly. Moreover, each one of the storage objectcontrol units, upon activation with power supply, can obtain the controlmanagement information needed for itself, so that by using this obtainedcontrol management information, the unit can appropriately control thecontrolled object assigned thereto.

Therefore, with the above-described construction, each control unit canappropriately control a controlled object assigned thereto, and also thereduction of the number of writable nonvolatile memories can berealized. As a result, it has become possible to provide a controlsystem for a working machine, which allows simplification and costreduction.

According to one preferred embodiment of the present invention:-

said information management control unit executes said controlmanagement information distributing process until lapse of apredetermined management setting period after the activation with powersupply, and after the lapse of said management setting period, saidinformation management control unit executes a control informationcommunicating process for transmitting/receiving said controlinformation; and

each one of said storage object control units executes said controlmanagement information obtaining process until lapse of thepredetermined management setting period after the activation with powersupply, and after the lapse of said management setting period, saidstorage object control units executes a control informationcommunicating process for transmitting/receiving said controlinformation.

That is to say, the information management control unit executes thecontrol management information distributing process until lapse of apredetermined management setting period after the activation with powersupply, and each one of said storage object control units executes thecontrol management information obtaining process until lapse of thepredetermined management setting period after the activation with powersupply. Therefore, during the period from activation with power supplyto the lapse of the predetermined management setting period, eachcontrol unit can communicate the control management information in aconcentrated manner. And, after the lapse of the predeterminedmanagement control period, each one of the storage object control units,having obtained the control management information appropriately, canexecute the control information communicating process.

Therefore, with effective utilization of the period immediately afterthe power supply, the control management information can be communicatedin a concentrated manner, so that it has become possible to provide acontrol system capable of effecting control operations as a whole.

According to one preferred embodiment of the present invention:-

said control management information includes a plurality of kinds ofcontrol management information;

in said control management information obtaining process, said eachstorage object control unit transmits a plurality of kinds of requestinformation according to a predetermined sequence, said plurality ofkinds of request information requesting said plurality of kinds ofcontrol management information respectively; and

in said control management information distributing process, when saidinformation management control unit is transmitting said plurality ofkinds of control management information according to the predeterminedsequence, if none of the plurality of storage object control units istransmitting any request information requesting any one of the pluralitykinds of control management information, said information managementcontrol unit transmits the kind of control management information in thesubsequent order in the predetermined sequence.

That is to say, for the communication of the plurality of kinds ofcontrol management information, the storage object control unittransmits request information requesting the kind of control managementinformation in the first order in the sequence and the informationmanagement control unit first transmits this kind of control managementinformation in the first order. Upon receipt of this kind of controlmanagement information in the first order, the storage object controlunit will transmit request information requesting a kind of controlmanagement information in the subsequent order in the sequence. In this,if any one of the plurality of storage object control units isrequesting this kind of control management information, the informationmanagement control unit will transmit this kind of control managementinformation. If none of the plurality of storage object control units istransmitting the request information requesting this kind of controlmanagement information, then, the kind of control management informationin the subsequent order will be transmitted.

And, with repeated execution of the above-described processes, when anyof the storage object control units is not receiving any kind of controlmanagement information of the plurality of kinds of control managementinformation, the information management control unit effectstransmission of that kind of control management information. So, eachone of the plurality storage object control units can receive theplurality of kinds of control management information requested from thisunit, and all the storage object control units can receive the pluralityof kinds of control management information respectively.

Therefore, according to this construction, it has become possible toprovide a control system for a working machine that allows reliablecommunication of each one of the plurality of kinds of controlmanagement information to the plurality of storage object control units.

According to one preferred embodiment of the present invention:-

if each one of the storage object control units does not receive therequested kind of control management information in the controlmanagement information obtaining process, the storage object controlunit transmits repeatedly the request information corresponding to thatkind of control management information upon lapse of a predeterminedunit period.

That is, if each one of the storage object control units does notreceive the requested kind of control management information, thestorage object control unit transmits repeatedly the request informationcorresponding to that kind of control management information upon lapseof a predetermined unit period. Therefore, the information managementcontrol unit can judge repeatedly upon lapse of the predetermined unitperiod, which kind of control management information is requested by theplurality of storage object control units. Then, the plurality of kindsof control management information can be transmitted in a reliablemanner with reduced risk of omission of transmission. Consequently, theplurality of storage object control units can reliably receive theplurality of kinds of control management information.

Therefore, according to the above characterizing feature, it has becomepossible to provide a control system for a working machine with whichthe information management control unit can transmit the plurality ofkinds of control management information in a reliable manner and theplurality of storage object control units can receive each one of theplurality of kinds of control management information in a reliablemanner.

According to one preferred embodiment of the present invention:-

the storage object control unit includes a ROM (read-only-memory) forstoring alternative control management information; and if the storageobject control unit fails to receive the control management informationfor its own to be transmitted from the information management controlunit even after the lapse of said management setting period, the storageobject control unit controls the controlled object assigned thereto,based on the alternative control management information stored in saidROM.

That is, if the storage object control unit does not receive the controlmanagement information for its own even after lapse of the managementsetting period, the storage object control unit controls the controlledobject assigned thereto based on the alternative control managementinformation stored in the ROM provided therein. Therefore, even in theevent of communication abnormality such as a trouble or communicationerror in the data communication network, it is possible to avoid thestorage object control unit being shifted into the state for controllingthe controlled object assigned thereto without obtaining the controlmanagement information. And, in this case, the storage object controlunit can control the controlled object assigned thereto, based on thealternative control management information.

Referring further to the alternative control management information, inthe case of fine adjustment data as an example of the control managementinformation, a standard value which is an intermediate value in therange of dispersion due to individual differences among a plurality ofworking machines can be used as the alternative control managementinformation, for example.

With this construction, there can be provided a control system for aworking machine wherein even in the event of communication abnormalityor trouble, the storage object control unit can control the controlledobject assigned thereto with using the control management information.

According to one preferred embodiment of the present invention:-

a specified storage object control unit among the storage object controlunits includes a writable nonvolatile memory for storing the controlmanagement information for its own; and

said specified storage object control unit stores in said nonvolatilememory the control management information for its own transmitted bysaid control management information obtaining process; and if thecontrol management information for its own to be transmitted from theinformation management control unit is not received even after the lapseof said management setting period, the controlled object assignedthereto is controlled based on control management information stored insaid nonvolatile memory.

That is to say, the specified storage object control unit stores in thenonvolatile memory the control management information for its owntransmitted by the control management information obtaining process. Inthis way, after storage of the control management information, if thecontrol management information for its own to be transmitted from theinformation management control unit is not received even after lapse ofthe management setting period, the controlled object assigned thereto iscontrolled, based upon the control management information stored in thenonvolatile memory. Therefore, even in the event of communicationtrouble such as a trouble or communication error in the datacommunication network, the controlled object assigned thereto can becontrolled appropriately, based upon the control management informationstored in the memory.

That is to say, if a control unit to be assigned with an especiallyimportant control among the plurality of control units is set as thespecified storage object control unit to store the control managementinformation in its nonvolatile memory, it becomes possible to store thecontrol management information in an overlapped manner in each one ofthe nonvolatile memories provided in each information management controlunit and the specified storage object control unit. Hence, whencommunication from the information management control unit is disableddue to communication abnormality or the like, appropriate controlmanagement information can be obtained with using the stored contents ofthe nonvolatile memory included in the specified storage object controlunit, so that the controlled object assigned thereto can be controlledfavorably.

Hence, it is possible to provide a control system for a working machinewith which even in the event of occurrence of communication trouble inthe data communication network, as the control management information isstored in the nonvolatile memory provided in the specified storageobject control unit, the controlled object can be controlledappropriately.

According to one preferred embodiment of the present invention:-

said specified storage object control unit includes a ROM for storingalternative control management information; and when control managementinformation for its own is not stored in the ROM provided in thespecified storage object control unit, if the control managementinformation for its own cannot be received from said informationmanagement control unit even after lapse of said management settingperiod, the controlled object assigned thereto is controlled based onthe alternative control management information stored in said ROM.

That is to say, when the control management information is not stored inthe nonvolatile memory provided in the specified storage object controlunit, if the control management information for its own cannot bereceived from the information management control unit even after lapseof the management setting period, the specified storage object controlunit controls the controlled object assigned thereto based on thealternative control management information stored in the ROM. Therefore,even when the control management information for its own is not storedin the nonvolatile memory provided in the specified storage objectcontrol unit, in the event of communication trouble such as a trouble orcommunication error in the data communication network, the controlledobject assigned thereto can be controlled based upon the alternativecontrol management information.

Therefore, it has become possible to provide a control system for aworking machine with which by adopting the double safety measure ofstoring the control management information in the nonvolatile memoryprovided in the specified storage object control unit and storingcontrol management information in the ROM (read-only-memory), thecontrol of the controlled object can be effected in even more reliablemanner, in the event of communication trouble in the data communicationnetwork.

According to one preferred embodiment of the present invention:-

said control management information includes information relating to themodel type of the working machine.

That is to say, since the control management information includesinformation relating to the model type of the working machine, each oneof the plurality of storage object control units can effect appropriatecontrol according to the model type of the working machine mounted.

More particularly, in many cases, the basic contents of control executedby the plurality of control units to be provided in a working machineremain the same regardless of the model type, whereas additional controlcontents to be added to the basic control contents differ according tothe working machine model type. Then, as the plurality of control unitsinclude a plurality of kinds of additional control contents to be ableto cope with a plurality of model types of working machines and storethe information of the model types in the nonvolatile memory, once themodel type information is given, control according to that workingmachine mode type can be effected.

Further, in case the working machine model type information is stored asthe alternative control management information, the information of onlythe basic control contents described above is to be stored, so that thecontents can be used commonly by any model type of working machine.

Therefore, it has become possible to provide a control system for aworking machine with which cost reduction is made possible by sharingthe information by/among different model types of working machines.

According to one preferred embodiment of the present invention:-

said working machine includes an actuator acting as said controlledobject capable of moving a controlled body; and a potentiometer typedetecting sensor acting as said information inputting means fordetecting an operated position of said controlled body;

said storage object control unit controls said actuator based ondetection information of said detecting sensor, and communicates as saidcontrol management information, to said information management controlunit, fine adjustment data for adjusting individual difference indetection value of the detecting sensor when said controlled body isoperated to a reference position by said actuator.

That is to say, as the control management information, fine adjustmentdata for adjusting individual difference in the detecting sensordetection value when said controlled body is operated to a referenceposition by the actuator, can be stored in the nonvolatile memory; andthe storage object control unit, when effecting the control of movementof the controlled body by the actuator, can detect the operated positionof the controlled body by the detecting sensor as an appropriate valuetaking the individual difference into consideration, with using the fineadjustment data communicated from the information management controlunit.

Therefore, there can be realized a control system for a working machinethat allows the storage object control unit to effect appropriately thecontrol, through activation of the actuator based on detectioninformation of the detecting sensor.

According to one preferred embodiment of the present invention:-

said storage object control unit executes a fine adjustment dataobtaining process for updating said fine adjustment data; and whenupdating fine adjustment data are obtained by this fine adjustment dataobtaining process, these fine adjustment data are communicated to saidinformation management control unit.

That is to say, as the storage object control unit executes the fineadjustment data obtaining process, fine adjustment data for updating canbe obtained. For instance, if repair/replacement has been made due to atrouble developed in the detecting sensor for detecting controlmanagement information, new fine adjustment data corresponding to adetection condition after that repair/replacement can be obtained. Then,when the new fine adjustment data have been obtained by this fineadjustment data obtaining process, this fine adjustment data will becommunicated to the information management control unit, so as to bewritten in the writable nonvolatile memory. After the storage of the newfine adjustment data in this way, the storage object control unit canreceive, by communication, the new fine adjustment data from theinformation management control unit.

Therefore, there can be realized a control system for a working machine,with which even when a repair/replacement has been done due to e.g. atrouble developed in the detecting sensor, the storage object controlunit can receive appropriate fine adjustment data from the informationmanagement control unit and can effect its control through an operationof the actuator based on the detection information of the detectingsensor.

According to one preferred embodiment of the present invention:-

the system further comprises an engine control unit for controlling anengine mounted on a work vehicle as said working machine, said enginecontrol unit being provided separately from said information managementcontrol unit and said storage object control unit;

said information management control unit communicates to said enginecontrol unit as said control information, control switchover instructinginformation, target rotational speed information and acceleratoroperational amount information; and

based on said control switchover instructing information communicatedfrom said information management control unit, said engine control unitis switchable between a state for executing an isochronous control formaintaining an output rotational speed of the engine at a targetrotational speed and a state for executing a droop control for adjustingthe output rotational speed of the engine to a speed corresponding to anaccelerator operational amount.

That is to say, from the information management control unit to theengine control unit, there are communicated control switchoverinstructing information, a target rotational speed information and anaccelerator operational amount information. And, based upon the controlswitchover instructing information, the engine control unit is switchedover between the state for executing the isochronous control and a statefor executing the droop control.

In the state for executing the isochronous control, the engine controlunit controls the engine to maintain its output rotational speed at atarget rotational speed communicated from the information managementcontrol unit. If the engine is maintained at the target rotational speedin this manner, when a work is to be carried out by driving theimplement, this work can be done in favorable manner with the stablerotational speed. For instance, if a combine is employed as the workingmachine, a harvesting operation can be carried out favorably at a stablerotational speed.

In the state for executing the droop control, the engine control unitcontrols the engine to adjust its output rotational speed to a speedcorresponding to an accelerator operational amount communicated from theinformation management control unit. If the speed is adjusted to thespeed corresponding to the accelerator operational amount in this way,the engine can be controlled at a rotational speed as desired by theoperator. For instance, if a combine is employed as the working machine,it can be caused to travel at an appropriate rotational speed adjustedby a manual adjustment, in the case of traveling on a road.

Therefore, it has become possible to provide a control system for aworking machine that allows controlling an engine to an appropriaterotational speed according to a use condition of the working machine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall side view of a combine using a control systemaccording to the present invention,

FIG. 2 is a view showing a construction of a threshing apparatus of thecombine,

FIG. 3 is a side view showing a front portion of the combine,

FIG. 4 is a side view of a traveling device of the combine,

FIG. 5 is a side view of the traveling device of the combine,

FIG. 6 is a side view of the traveling device of the combine,

FIG. 7 is a plan view of a bundling device of the combine,

FIG. 8 is a rear view of the bundling device of the combine,

FIG. 9 is a view showing a transmission construction of the combine,

FIG. 10 is a control block diagram of the combine,

FIG. 11 is a flowchart of control operation,

FIG. 12 is a flowchart of control operation,

FIG. 13 is a flowchart of control operation,

FIG. 14 is a flowchart of control operation,

FIG. 15 is a flowchart of control operation,

FIG. 16 is a flowchart of control operation,

FIG. 17 is a flowchart of control operation,

FIG. 18 is a flowchart of control operation,

FIG. 19 is a block diagram of an engine control system of a tractorpulling a rotary plow implement,

FIG. 20 is a view for explaining data stored respective memories of anengine control unit and a separate control unit of the control systemshown in FIG. 19, and

FIG. 21 is a flowchart illustrating a process for controlling a fuelsupply amount by the engine control unit of the control system shown inFIG. 19.

BEST MODE FOR CARRYING OUT THE INVENTION

Next, with reference to the accompanying drawings, there will bedescribed an embodiment in which the control system of the invention isapplied to a combine as an example of the working machine.

As shown in FIG. 1, in this combine, to a front portion of a machinebody V having a pair of right and left crawler type traveling devices1R, 1L, there is attached a harvesting section 2, with this section 2being vertically pivotable about a horizontal axis P1 by means of aharvesting lift cylinder CY1 as an actuator. Rearwardly of thisharvesting section 2, there are mounted an operational section 3, athreshing section 4 for threshing/sorting harvested culms, a grain tank5 for reserving therein grains to be fed from the threshing section 4, agrain discharging unloader 6 for discharging the grains from within thegrain tank 5, a bundling device 7 for bundling waste straws after thethreshing by a predetermined amount and discharging the bundled strawsto the outside of the machine, etc.

The harvesting section 2 includes a grass divider 8 attached to theleading end thereof, a culm raiser 9, a cutting blade 10 for cutting theroots of the raised culms and a conveying device 11 for receiving theharvested culms adjacent the leading end thereof and then conveying themto the threshing section 4. Further, a potentiometer type harvestinglift position sensor S1 is provided for detecting the lift position ofthe harvesting section 2 relative to the machine body V based on a pivotangle about the horizontal axis P1.

Further, the harvesting section 2, as shown in FIG. 10, includes aground-contacting type harvesting height sensor S2 for detecting aheight of the harvesting section 2 as measured from the ground surface,and a stock root sensor S3 activated upon contact with harvested culmsto detect that a harvesting operation is going on. The operationalsection 3 includes a harvesting height setter 12 for setting a targetharvesting height. The information detected by the harvesting heightsensor S2 on the height of the harvesting section 2 from the groundsurface is used for harvesting height control in harvesting culms. Moreparticularly, when harvesting control is started with the provision ofthe lift position of the harvesting section 2 relative to the machinebody V being lower than a predetermined position, the harvesting liftcylinder C1 will be controlled such that the detection value of theharvesting height sensor S2 may be rendered to a target harvestingheight set by the harvesting height setter 12.

As shown in FIG. 1, the operating section 3 includes a cross-operationtype harvesting height steering 13 acting as a harvesting lift lever formanually lifting up/down the harvesting section 2 and acting also as asteering lever for manually steering the traveling machine body to theright/left. In operation, when this harvesting height steering lever 13is pivoted to the rear side, an elevating switch 14 (see FIG. 10) isturned ON to elevate the harvesting section 2. When the lever 13 ispivoted to the forward side, a lowering switch 15 (see FIG. 10) isturned ON to lower the harvesting section 2.

As shown in FIG. 3, the conveying device 11 supports a conveying section11 a disposed at the conveying terminal end thereof, with the section 11a being pivotable about a vertical axis and pivotally adjustable bymeans of a threshing depth motor M1 as an actuator. Further, an ear-tipside culm sensor S4 for detecting the ear tip position of the conveyedculms and a root side culm sensor S5 are provided with positional offsetrelative to each other in the culm length direction. Then, by changingthe delivering position by the conveying section 11 a to the threshingsection 4 along the culm length direction to an appropriate conditionthat the ear tips of the conveyed culms may be located between these twosensors S4, S5, the threshing depth at the threshing section 4 can beadjusted and the threshing depth at the threshing section 4 can bemaintained under the proper condition. Further, there is provided arotational potentiometer type threshing depth position sensor S6 (seeFIG. 10) for detecting the threshing depth adjusted position provided bythe threshing depth sensor M1.

Referring to the left-side traveling device 1L as shown in FIG. 4, onthe front end side of a fore/aft oriented main frame 16 constituting themachine body V, a drive sprocket 17 is rotatably mounted. A track frame20, pivotally mounting a plurality of free wheels 18 in juxtaposition inthe fore/aft direction and a tension wheel 19 supported at the rear endthereof for tensioning a crawler belt CB, is connected to be verticallypivotable to the main frame 16 by means of a front bell crank 21 a and arear bell crank 21 b. More particularly, a lower end portion of thefront bell crank 21 a is pivotally connected to a front portion of thetrack frame 20, and a lower end portion of the rear bell crank 21 b ispivotally connected to a rear portion of the track frame 20. On theother hand, to upper end portions of the respective front and rear bellcranks 21 a, 21 b, there are operably connected cylinder rods of a pairof hydraulic cylinders CY2, CY3 having cylinder bodies thereof pivotallyconnected to the main frame 16. The right-side traveling device 1R hasan identical construction.

Accordingly, as actuators, there are provided four hydraulic cylinders,i.e. the left front cylinder CY2 for lifting up/down the front portionof the left traveling device 1L the left rear cylinder CY3 for liftingup/down the rear portion of the left traveling device 1L, the rightfront cylinder CY4 for lifting up/down the front portion of the righttraveling device 1R and the right rear cylinder CY5 for lifting up/downthe rear portion of the right traveling device 1R. In operation, byexpanding/contracting these four hydraulic cylinders CY2-CY5, thefore/aft inclination angle and the right/left inclination angle of themachine body V relative to the ground surface can be changed. And, fourpotentiometer type stroke sensors S7-10 are provided for detecting liftoperational amounts by the respective cylinders CY2-CY5.

That is to say, as shown in FIGS. 4 and 5, if e.g. the left frontcylinder CY2 and the right front cylinder CY4 are stopped and the leftrear cylinder CY3 and the right rear cylinder CY5 areexpanded/contracted simultaneously, the fore/aft inclination angle ofthe machine body relative to the ground surface is changed. Further, asshown in FIG. 6, if the right front cylinder CY4 and the right rearcylinder CY5 are stopped and the left front cylinder CY2 and the leftrear cylinder CY3 are expanded/contracted simultaneously, the right/leftinclination angle of the machine body relative to the ground surface ischanged.

And, the machine body V, as shown in FIG. 10, includes a right/leftinclination angle sensor S11 for detecting a right/left inclinationangle of the machine body relative to the horizontal surface and afore/aft inclination angle sensor S12 for detecting a fore/aftinclination angle of the machine body relative to the horizontalsurface. And, a control operational panel section 22 provided in theoperational section 3 includes a posture control ON/OFF switch SW1 forinstructing execution/stop of posture control, a horizontal returnswitch SW2 for setting a target inclination angle to the horizontalstate, a harvesting control ON/OFF switch SW15 for instructingexecution/stop of harvest height control, and four manual operationswitches, i.e. a front up switch SW3, a rear up switch SW4, a left upswitch SW5 and a right up switch SW6, having the function of changingthe posture of the machine body by manual operations and the function ofchanging the target inclination angle during posture control, etc.

The threshing section 4, as shown in FIG. 2, includes a threshingchamber 24 accommodating a threshing drum 23, a feed chain 25 forconveying culms fed from the harvesting section 2, a sorting device 28composed of a winnowing fan 26 and a swing sorting plate 27, a primaryopening 29 for collecting grains and a secondary opening 30 forcollecting mixture of grains and exhaust straws, etc. And, the separatedgrains from the processed material threshed in the threshing chamber 24will fall through a receiving mesh or a ‘concave’ 31 provided at a lowerportion of the threshing chamber 24 onto the sorting device 28, and theremaining processed material will fall from the rear end of thereceiving mesh 31 onto the sorting device 28.

The swing sorting plate 27 of the sorting device 28 includes a grain pan32 disposed upwardly of the winnowing fan 26 for conveying the processedmaterial dropped from the threshing chamber 24 to the rear side of themachine body, a chaff sieve 33 disposed rearwardly of the grain pan 32for effecting rough sorting of the processed material, a grain sieve 34disposed downwardly of the chaff sieve 33 for effecting fine sorting ofthe processed material, etc.. The chaff sieve 33 comprises a pluralityof band plate-like members juxtaposed along the conveying direction ofthe processed material and the distance between adjacent band plate-likemembers (i.e. the chaff opening degree) is varied by a chaff openingdegree adjusting motor M2 as an actuator. And, for detecting this chaffopening degree, there is provided a chaff opening degree sensor S 13(see FIG. 10) utilizing a potentiometer.

The winnowing fan 26 is for belowing away straw chaffs on the swingsorting plate 27. When a rear side fan case cover 26 a is opened/closedby a winnowing fan wind force adjusting motor M3 as an actuator, thewind force (referred to as “winnowing force”) applied to the processedmaterial on the swing sorting plate 27 is varied in such manner that thegreater the opening degree, the smaller the wind force toward the frontside. And, a winnowing force sensor S14 (see FIG. 10) using apotentiometer is provided for detecting the winnowing fan wind force bydetecting the opening degree of this fan case cover 26 a. Further, asieve sensor S15 is provided for detecting the layer thickness of theprocessed material on the swing sorting plate 27.

As shown in FIG. 1, the unloader 6 includes a downwardly orienteddischarge opening 6 a at the leading end thereof, and a base end portionof the unloader 6 is supported to a support portion 35 to be verticallypivotable about a horizontal axis P2 by an unloader lift cylinder CY6and this support portion 35 is pivoted to the machine body V to beswivellable about a vertical axis Y by an unloader swivel motor M4. And,there are provided an unloader position sensor S16 comprised of apotentiometer for detecting a swivel position of the support portion 35and an unloader upper limit sensor S17 for detecting the unloader 6being at its upper limit position (see FIG. 10).

Further, as shown in FIG. 10, an unloader operating panel section 36provided in the operational section 3 includes a projecting switch SW7for moving the unloader 6 to an outwardly projected position, a storingswitch SW8 for moving the unloader 6 to its home position, a rightswiveling instructing switch SW9 for manually instructing rightswiveling, a left swiveling instructing switch SW10 for manuallyinstructing left swiveling, an elevating instructing switch SW11 formanually instructing an elevating operation, a lowering instructingswitch SW12 for manually instructing a lowering operation, an unhulledrice discharging switch S13 for instructing ON/OFF of an unhulled ricedischarging clutch, etc.

Referring next briefly to the power transmission mechanism, as shown inFIG. 9, the output of an engine E is transmitted via a threshing clutch37 to the threshing section 4 and also transmitted via a main clutch 38to a transmission section 39. The transmission section 39 includes astepless speed-changing device 41 (HST) for effecting speed changingoperation in response to an operation of a speed-changing operationalmember 40, and includes also a turning condition switchover mechanism 42having the well-known construction, which can be switched over into aslow turning condition (or a grand turning condition) in which onetraveling device is driven at a lower speed than the other travelingdevice, a braked turning condition in which one traveling device 1 iskept under the braked condition, and a reverse turning condition inwhich one traveling device is driven in the opposite condition to thatof the other traveling device. Although explanation of details of thisturning condition switchover mechanism 42 will be omitted, thismechanism includes a hydraulic clutch for the slow turning for switchingover to the slow turning condition, a hydraulic clutch for the brakedturning for switching over to the braked turning condition, a hydraulicclutch for the reverse turning for switching over to the reverse turningcondition, etc. and includes also a hydraulic control section 43 havinga plurality of hydraulic control valves for switching over pressure-oilconditions to these respective hydraulic clutches. Further, there isprovided a threshing clutch sensor S18 (see FIG. 10) for detectingON/OFF state of the threshing clutch 37.

The switching operations of the turning condition switchover mechanism42 are effected by right/left pivotal operations of the harvestingheight steering lever 13 provided in the operational section 3. That is,there is provided a potentiometer type steering lever sensor S19 (seeFIG. 10) for detecting a right/left pivotal operational amount of theharvesting height steering lever 13 and in response to an operation ofthe harvesting height steering lever 13, the turning conditionswitchover mechanism 42 is switched over.

The bundling device 7, as shown in FIG. 7 and FIG. 8, includes abundling machine 44 for bundling exhaust straws discharged from thethreshing section 4 by the exhaust straw conveying device 7A by apredetermined amount; a stock leveling mechanism 45 for leveling, i.e.rendering uniform the root ends of the exhaust straws by tapping onthem; a thread-feeding type position adjusting mechanism 46 capable ofadjusting the position of the stock leveling mechanism 45 along the culmlength direction of the exhaust straws; and a pair of exhaust strawdetecting sensors S20, S21 for detecting whether the stock end positionof the exhaust straws is located at an appropriate position relative tothe bundling machine 44. Further, this bundling device 7 includes apotentiometer type stock leveling position detecting sensor S22 fordetecting the position of the stock leveling mechanism 45 in the exhauststraw culm length direction. Though not to be described in details, anarrangement is provided such that based upon information of this stockleveling position detecting sensor S22, the position of the conveyingterminal end of the exhaust straw conveying device is varied so as torender the bundling position to an appropriate position.

And, there are provided in distribution, a plurality of control unitscapable of communicating with each other via a data communicationnetwork TU. And, each one of the plurality of control units effectscontrolling of a controlled object assigned respectively thereto, basedupon input information inputted by information inputting means providedtherein, control information communicated from a further (i.e. non-self)control unit, and control management information.

For instance, a main control unit H1 for controlling e.g. the harvestinglift cylinder C1, etc. is disposed adjacent the harvesting section 2. Amachine control unit H2 for controlling the unloader 6 is disposedadjacent the grain tank 5. A posture control unit H3 is disposedadjacent the disposing positions of the hydraulic cylinders for posturecontrol. A threshing control unit H4 for controlling the threshingsection 3 is disposed in the threshing section 3. A bundling controlunit H6 is disposed adjacent the bundling device 7, and so on. In thisway, a plurality of control units are disposed in distribution in therespective vicinity of the controlled objects assigned respectivelythereto.

More particularly, as shown in FIG. 10, as the plurality of controlunits H, there are provided the main control unit H1, the machinecontrol unit H2, the posture control unit H3, the threshing control unitH4, the traveling control unit H5, the bundling control unit H6 and anengine control unit H7, respectively. And, each one of these controlunits includes a microcomputer and is capable of communicatinginformation via an unillustrated communication module provided therein;and via the data communication network TU of the CAN (Controller AreaNetwork) type, comprising communication bus lines 47 connected to thecommunication module. Further, the control operation panel 22 providedin the operational section 3, the unloader operation panel section 36,and a display panel section 46 for displaying various kinds ofinformation, are capable of communicating information via the datacommunication network TU.

Referring briefly to the communication data communicated via the datacommunication network TU, the communication data comprise a plurality ofbit sequences of data including the other party address data forspecifying the other party for transmission, control contentsinformation indicating control contents to be processed, and specificcontrol data (numeric data, etc.).

Next, the respective control units will be described.

The main control unit H1 executes harvesting height control, whenactivated by conditions of an ON operation of the harvesting controlON/OFF switch SW15 provided in the control operation panel section 22and of the height of the harvesting section 2 detected by the harvestinglift position sensor S1 being lower than a set height. That is, thesection H1 controls the harvesting lift cylinder C1 as its controlledobject based upon the information from the harvesting height sensor S2as information inputting means so that the harvesting height of theharvesting section 2 may be maintained at the target set height.Further, the main control unit H1 controls the harvesting lift cylinderC1 so that the harvesting section 2 is elevated in response to an ONoperation of the elevating switch 14 and the harvesting section 2 islowered in response to an ON operation of the lowering switch 15. Thedetection information of the elevating switch 14 and the lowering switch15 is inputted to the machine control section H2, as shown in FIG. 10and these detection data are communicated as control information to themain control unit H1.

The machine control unit H2 executes the threshing depth control whenactivated by conditions of an ON operation of a threshing depthautomatic switch SW14 provided in the control operation panel section 22and of an ON operation of the stock root sensor S3. In this, based uponthe information of the ear-tip side culm sensor S4 and the root sideculm sensor S5 as the information inputting means, the threshing depthmotor M1 as an actuator will be controlled such that the ear-tipposition of the conveyed culms may be appropriately between the sensorsS4, S5.

Further, the machine control section H2 controls the unloader 6, inaddition to the threshing depth control. That is, the movements of theunloader 6, such as swiveling, lifting up/down, storing, correspondingto the operational instructions from the respective operational switchesprovided in the unloader operational panel section 36 will becontrolled. In this, based upon the detection information of theunloader position sensor S16 and the unloader upper limit sensor S17 asthe information inputting means, the unloader lift cylinder CY6 and theunloader swiveling motor M4 will be controlled as actuators.

The posture control unit H3 starts the posture control in response to anON operation of the posture control ON/OFF switch SW1 provided in thecontrol operational panel section 22; and the unit H3 controls, based onthe right/left inclination angle sensor S11 and the fore/aft inclinationangle sensor S12 as the information inputting means, the four cylindersC2-C5 as machine body posture changing actuators so that the fore/aftinclination angle and the right/left inclination angle of the machinebody V may be rendered to the respective target inclination angles.Further, if any one of the manual operational switches SW3-SW6 isoperated under the OFF state of the posture control ON/OFF switch SW1,one of the hydraulic cylinders will be controlled so that the posturewill be changed to the instructed direction while the switch is beingoperated. During execution of the posture control, if any one of themanual operational switches SW3-SW6 is operated, the posture will bechanged to the instructed direction. The posture realized at the time ofstop of this operation will be newly set as a target inclination angle.

The threshing control unit H4 executes threshing control, by theconditions of the threshing clutch 37 being engaged and of the rootsensor S3 being ON. In this threshing control, based upon theinformation of the sieve sensor S15 as the information inputting means,the chaff opening degree adjusting motor M2 and the winnowing fan windforce adjusting motor M3 will be controlled so as to obtain anappropriate layer thickness on the sieve. The detection information ofthe root sensor S3 will be inputted to the main control unit H1 as shownin FIG. 10, and this detection information is communicated as controlinformation to the threshing control unit H4.

Based upon information of the steering lever sensor S19 as informationinputting means, if an instruction for straight traveling is given, thetraveling control unit H5 switches the turning condition switchingmechanism 42 to straight traveling condition, whereas, if an instructionfor turning is given, the unit H5 switches the turning conditionswitching mechanism 42 to a turning condition and also switches theturning condition switching mechanism 42 to provide a turning forcebased on information from the steering lever sensor 13, in the course ofwhich the hydraulic control section 43 is controlled.

The bundling control unit H6 executes bundling control. In this bundlingcontrol, the position adjusting mechanism 46 is controlled so that thestock end position of the exhaust straws may be at an appropriateposition, that is, a condition that only one sensor S20 of the exhauststraw detecting sensor S20, S21 located on the side of the culms beingpresent detects the presence of exhaust straws. Simultaneously, based onthe information from the stock leveling position detecting sensor S22,the conveying end position of the exhaust straw conveying device 7A isalso controlled.

The engine control unit H7 receives, as the control information from themain control unit H1, control switchover instruction information, targetrotational speed information and accelerator operational amountinformation. Based upon the control switchover instruction information,a mode of executing the isochronous control for maintaining the outputrotational speed of the engine E at a target rotational speed and a modefor executing the droop control for adjusting the output rotationalspeed of the engine E to a speed corresponding to an acceleratoroperational amount are switched over therebetween. Further, to thisengine control unit H7, control management information such as a modeltype data, fine adjustment data etc. to be described later, are nottransmitted. Rather, such information are stored in an unillustratedmemory for the engine.

To add some explanation, the main control unit H1 receives detectioninformation of a potentiometer type accelerator setter 49 which can bevariably set by a manual operation and detection information of thethreshing clutch sensor S18, and transmits these information as controlinformation to the engine control unit H7. If the threshing clutchsensor S18 detects clutch engaged condition, then, an instruction forexecuting the isochronous control will be issued. Whereas, if thethreshing clutch sensor S18 detects a clutch disengaged condition, aninstruction for executing the droop control will be issued.

To the engine control unit H7, detection information of the rotationalspeed sensor S23 for detecting the rotational speed of the engine E isinputted. And, if an executing instruction for the isochronous controlis transmitted from the main control unit H1 as control switchoverinstructing information, the engine E will be controlled such that itsoutput rotational speed is maintained to the target rotational speedwhich was set in advance to a value suitable for a work. Specifically,the fuel supply amount by an electronic governor 55 is adjustablycontrolled. On the other hand, if an executing instruction for the droopcontrol is transmitted as the control switchover instructinginformation, the fuel supply amount by the electronic governor 55 iscontrolled for adjusting the output rotational speed of the engine E toa speed corresponding to an accelerator operational amount.

As described above, the information of the stock root sensor S3 inputtedto the main control unit H1 is communicated via the data communicationnetwork to the threshing control unit H4. As an example of other controlinformation than the above to be communicated from a further controlunit, there is information for enabling the further control unit tocontrol the control condition of the one control unit. For instance, theposture control unit H3 executes the posture control for rending theright/left inclination angle of the machine body V to a targetinclination angle. In this, the right/left target inclination angle ofthe machine body will be changed by a manual operation, so that a targetinclination angle inclined to either right or left side no smaller thana set angle relative to the horizontal posture will be set. In suchcase, this information is transmitted as control information to the maincontrol unit H1. The main control unit H1 executes a target harvestingheight correcting process for correcting the target harvesting height toa value higher by a predetermined amount than the value set by theharvesting height setter 12. In addition to the above-describedinformation, various kinds of information are transmitted as controlinformation.

And, the main control unit H1 sets one or some of all the other controlunits of the plurality of control units, i.e. the machine control unitH2, the posture control unit H3, the threshing control unit H4, thetraveling control unit H5 and the bundling control unit H6, as storageobject control units. Further, the main control unit H1 is set as theinformation management control unit having a nonvolatile memory 50 as awritable nonvolatile memory for storing the control managementinformation of such other respective control units as well as thecontrol management information for its own. Upon activation with powersupply, this main control unit H1 executes a control managementinformation distributing process for transmitting the control managementinformation stored in the nonvolatile memory 50 to the storage objectcontrol units via the data communication network TU. Then, each one ofthe storage object control units, upon activation with power supply,executes a control management information obtaining process. In thiscontrol management information obtaining process, the storage objectcontrol unit receives the control management information for its ownfrom the main control unit H1 via the data communication network TU. Thenonvolatile memory 50 comprises an electrically writable and erasableEEPROM or a flash memory.

And, as examples of the control management information to be stored inthe nonvolatile memory 50, there are model type data which areinformation of the machine model type, fine adjustment data which arethe information for use in adjustment of individual unit difference indetection values of the detecting sensors when the controlled body isoperated to the reference position by the actuator, and control settingdata relating to a width of control-insensitive area at the time ofexecution of control.

Further, the main control unit H1 has a function of storing in thenonvolatile memory 50, the detection value of the harvesting liftposition sensor S1 when the harvesting section 2 is lifted to its upperlimit position.

The detection values of the threshing depth sensor S6 when the conveyingdevice 11 as the controlled body is moved by operation of the threshingdepth motor M1 to the deepest threshing position and the shallowestthreshing position; and the detection value of the unloader positionsensor S16 when the unloader 6 is swiveled to its home position, etc.are transmitted as examples of the fine adjustment data from the machinecontrol unit H2 to the main control unit H1 and stored in thenonvolatile memory 50.

The detection values of the stroke sensors S7-S10 are transmitted, asfurther examples of the fine adjustment data, from the posture controlunit H3 to the main control unit H1, when the respective cylinders asthe controlled objects are operated to the uppermost position and thelowermost position. And, these transmitted data are stored in thenonvolatile memory 50. Further, as the control setting data, theinformation of the width of control-insensitive area at the time ofexecution of the posture control is also transmitted to the main controlunit H1 and stored in the nonvolatile memory 50.

The detection values of the chaff opening degree sensor S13, as furtherexamples of the fine adjustment data, are transmitted from the threshingcontrol unit H4 to the main controller H1, when the chaff sieve 33 isoperated to the full open position and full closed position respectivelyas the reference positions. And, these transmitted data are stored inthe nonvolatile memory 50.

As further examples of the fine adjustment data, the detection value ofthe steering lever sensor S19 when the harvesting height steering lever13 is operated to the maximum turning operational position as thereference position; and the detection value of the steering lever sensorS19 at a position corresponding to the straight traveling aretransmitted from the traveling control unit H5 to the main control unitH1. And, these transmitted data are stored in the nonvolatile memory 50.As an example of the control setting data, information of thecontrol-insensitive area under the neutral condition for maintaining thestraight traveling condition is transmitted to the main control unit H1,and stored in the nonvolatile memory 50.

As a further example of the fine adjustment data, the detection valuesof the stock leveling position detecting sensor S22 when located at theends at the opposed sides in the exhaust straw culm length direction asthe references positions are transmitted from the bundling control unitH6 to the main control unit H1 and stored in the nonvolatile memory 50.

Further, each one of the storage object control units (H2-H6) executes afine adjustment data obtaining process for updating the fine adjustmentdata; and when new fine adjustment data for updating is obtained by thisfine adjustment data obtaining process, the unit transmits this fineadjustment data to the information management control unit. That is, incase e.g. a trouble occurred in any of the various detecting sensors asthe information inputting means with continued use of the combine andreplacement thereof has been done, the storage object control unit(H2-H6) newly obtains the fine adjustment data by executing the fineadjustment data obtaining process.

Though not shown, referring further to the fine adjustment dataobtaining process, the storage object control unit is switched over to acontrol mode for obtaining fine adjustment data, in response to aspecial input operation such as a power supply with continued depressionof a maintenance switch, for example. And, the actuator or the like(hydraulic cylinder, electric motor, etc.) will be controlled so as toprovide an operational mode for fine adjustment detection in thatcontrol mode; and a detection value of the repaired and newly replaceddetecting sensor, when the controlled body is operated to its referenceposition, is obtained as the updating fine adjustment data. And, whensuch updating fine adjustment data have been obtained, this updatingfine adjustment data will be transmitted to the main control unit H1 andstored in its nonvolatile memory 50.

The fine adjustment data described above are transmitted from thestorage object control units (H2-H6) to the main control unit H1 andstored in its nonvolatile memory 50. In this, if the communication bythe data communication network TU is not effected properly, fineadjustment data may not be obtained. To cope with this, there isprovided a read-only memory (ROM) for storing alternative controlmanagement information. In operation, if no control managementinformation for its own cannot be received from the main control unit H1even after lapse of a management setting period after activation withpower supply, the controlled object for its own will be controlled basedon this alternative control management information stored in the ROM.

Not only the storage object control units (H2-H6), but also the maincontrol unit H1 has such ROM for storing alternative control managementinformation. So, in case the control management information is notavailable from the nonvolatile memory 50, the controlled object will becontrolled based upon the alternative control management informationstored in the ROM.

As this ROM, there is employed a ROM storing a control program forcontrolling a controlled object assigned thereto. And, in this ROM 52,the control management information for its own is stored in advance. Asthe ROM 52, a mask ROM, a PROM, etc. can be used.

Incidentally, as the above-described fine adjustment data, the variouskinds of information described above are just non-limiting examples.Other kinds of information can be stored also. Further, theabove-described fine adjustment data are stored in advance at the timeof shipping from the factory, but may be stored when a repair, acomponent-replacement or the like has been carried out. That is, whenthe storage object control unit (H2-H6) has obtained updating fineadjustment data by the fine adjustment data obtaining process, this fineadjustment data will be transmitted to the main control unit H1 andstored in its nonvolatile memory 50. Further, the machine model typedata will be stored in advance in the nonvolatile memory 50, prior tothe shipping of the combine from the factory.

Further, of the respective control units, the traveling control unit H5corresponds to a “specified storage object control unit”. For instance,if the detection value of the operational position corresponding to thestraight traveling is not stored as a value appropriate for eachindividual machine, the machine or vehicle body may not travel straighteven if the harvesting height steering lever 13 is operated to thestraight traveling condition. Then, this traveling control unit H5stores the control management information transmitted from the maincontrol unit H1 in a writable nonvolatile memory 51 provided in thespecified storage object control unit for storing the control managementinformation for its own. This memory 51 can be an electrically writableand erasable EEPROM, a flash memory, etc.

Until lapse of a predetermined management setting period after theactivation with power supply (e.g. for 1.5 seconds), the main controlunit HI executes a control management information distributing processfor transmitting via the data communication network TU the controlmanagement information stored in the nonvolatile memory 50 to thestorage object control unit; and also, upon lapse of the managementsetting period, executes a control information communicating process fortransmitting/receiving the control information to/from the other controlunit. Further, until the lapse of the management setting period afteractivation with power supply, each one of the storage object controlunits (H2-H6) executes a control management information obtainingprocess for obtaining the control management information for its ownfrom the main control unit H1 via the data communication network TU; andalso, upon lapse of the management setting period, executes the controlinformation communicating process for transmitting/receiving the controlinformation.

Further, in the control management information obtaining process, thestorage object control unit (H2-H6) transmits a plurality of kinds ofrequest information respectively requesting the plurality of kinds ofcontrol management information according to a predetermined sequence. Inthis, upon receipt of a preceding sequence kind of control managementinformation, request information requesting the subsequent sequence kindof control management information is transmitted. When the plurality ofkinds of control management information are being transmitted accordingto the predetermined sequence in the control management informationdistributing process, if none of the plurality of storage object controlunits receives any kind of control management information, thesubsequent sequence kind of control management information will betransmitted.

Further, if each one of the storage object control units does notreceive the requested kind of control management information in thecontrol management information obtaining process, the requestinformation for that kind of control management information will betransmitted in repetition with each lapse of the setting unit timeperiod.

Next, the control operations by the main control unit H1 and the storageobject control units, after power-ON, will be specifically described.

First, the control contents of the main control unit H1 will bedescribed. As shown in FIG. 11, this main control unit H1 executes thecontrol management information distributing process until lapse of themanagement setting period (1.5 seconds) after the activation (steps #1,#2), and upon lapse of the management setting period after theactivation (1.5 seconds), the unit Hi executes a control informationreceiving process until the power is OFF and controls the controlledobject (e.g. the harvesting lift cylinder C1) assigned thereto (steps#3, #4, #5). Incidentally, in the control information receiving process,the same steps as in the above-described data receiving process will beexecuted. And, when the power is turned OFF, if there is some data to beupdated, the unit H1 executes an updating process of the nonvolatilememory 50 regarding the control management information (steps #6, #7).

Next, the control management information distributing process will bedescribed.

As shown in FIG. 12, upon initiation of the control managementinformation distributing process, the data receiving process and thedata transmitting process will be executed (steps #100, #101, #102). Thedata receiving process will be described later. The data transmittingprocess is a process for transmitting data set in a transmission bufferonto a communication bus line 47.

And, with each lapse of the set unit time (10 msec.), the data beingrequested by the plurality of storage object control units aretransmitted. That is, if any one of the storage object control units istransmitting request information for the machine model type data, then,the process makes preparation for transmitting the model type datastored in the nonvolatile memory 50 (steps #103, #104). Referring tothis transmission preparation, this is a process of setting data to betransmitted (the model type data) in the transmission buffer. With thissetting in the transmission buffer, these data will be transmitted ontothe communication bus line 47 in the data transmitting process at step3. The process will be carried out similarly, in the subsequenttransmission preparation.

If none of the plurality of storage object control units is transmittingthe model type request data requesting the model type data and any oneof them is transmitting the fine adjustment request data requesting fineadjustment data, then, the process makes preparation for transmittingthe fine adjustment data stored in the nonvolatile memory 50 (steps#107, #108). If none of the plurality of storage object control units istransmitting the fine adjustment requesting data, the process makespreparation for transmitting control setting data (step #109). Thispreparation for transmission of control setting data is effected inrepetition, with each lapse of the setting unit period (10 msec.) evenin the event of absence of request from any of the storage objectcontrol units.

Next, the data receiving process will be described.

As shown in FIG. 13, if the received data are data requestingtransmission of control management information (steps #200, #201) and ifthese received data are transmission data from the machine control unitH2, then, a data updating process corresponding to the machine controlunit H2 will be executed (steps #202, #203). This data updating processwill be executed as illustrated in FIG. 14. That is to say, the processdetermines which data the machine control unit H2 is requesting (step#300). If forwarding of fine adjustment execution result is beingrequested, and if the data representing the kind of fine adjustmentupdating data included in the data are normal and also the dataindicating the fine adjustment data are normal (not zero), the processmakes preparation for writing the fine adjustment data to be updated inthe nonvolatile memory 50 (steps #301, #302, #303). That is, the datawill be set in a buffer for writing. If such updating process iseffected, as described above, before the power is turned OFF, theupdating process of the control management information to thenonvolatile memory 50 will be effected (steps #4, #5).

And, such updating process of fine adjustment data will be effected foreach one of the data received from the other storage object controlunits, i.e. the posture control unit H3, the threshing control unit H4,the traveling control unit H5 and the bundling control unit H6 (steps#204 through #210).

With this main control unit Hi, when the control management informationfor its own cannot be received from the nonvolatile memory 50 in thecontrol information receiving process, appropriate control cannot beexecuted. Therefore, in such case, the data stored in the ROM 52 will beset as the control management information and the controlled object(harvesting lift cylinder C1, etc.) assigned thereto will be controlled.

Next, the control contents in the storage object control units (H2-H6)will be described.

As shown in FIG. 15, after activation with power supply, for the perioduntil lapse of the management setting period after the activation (1.5seconds), the control management information obtaining process isexecuted (steps #21, #22). And, if no control management information hasbeen obtained yet even after the lapse of the management setting periodafter the activation (1.5 seconds) or if the obtained control managementinformation exceeds a permissible range, thus being clearly an abnormalvalue, then, no appropriate control can be made. So, in that case, thedata stored in the ROM 52 will be set as the control managementinformation (steps #23, #24, #25). Thereafter, a process forcommunicating the control management information to the other controlunits will be effected until the power is OFF and, the controlled objectassigned to its own (e.g. the threshing depth motor M1) will becontrolled (steps #26, #27, #28).

Next, the control management information obtaining process will bedescribed.

As shown in FIG. 16, upon initiation of the control, the data receivingprocess and the data transmitting process will be carried out (steps#30, 31, 32). The data receiving process will be described later. Thedata transmitting process is a process for transmitting data set in thetransmission buffer onto the communication bus line 47.

And, with each lapse of the setting unit time (10 msec.), a transmittingprocess of request information requesting necessary information asfollows will be effected. That is, if the model type data are notreceived from the main control unit H1, the process makes preparationfor transmitting model type requesting data as the request datarequesting the model type data (steps #33, #34). If the model type dataare received, then, the process determines whether fine adjustment dataas the next order of control management information is received from themain control unit H1 or not; and if not received, the process makespreparation of transmission of fine adjustment request data as requestdata for requesting find adjustment data (steps #39, #40). If the fineadjustment updating data are received, then, the process determineswhether control setting data are received from the main control unit H1or not. If the control setting data are not received, then, the processmakes preparation for transmission of control setting informationrequesting data as requesting data requesting control setting data. Ifthe control setting data are received, the process makes preparation fortransmission of empty data (transmission data having zero in all dataareas thereof) (steps #41, #42, #43).

Therefore, if the storage object control unit does not receive therequested kind of control management information, the unit transmits inrepetition, upon every lapse of the setting unit period (10 msec.), therequesting information corresponding to that kind of control managementinformation.

Next, the data receiving process will be described. As the travelingcontrol unit H5 partially overlaps in its contents of this process withthe other storage object control units (H2, H3, H4, H6), the datareceiving processes of the other storage object control units (H2, H3,H4, H6) other than the traveling control unit H5 will be describedfirst.

That is, as shown in FIG. 17, if the received data are transmission dataof control management information from the main control unit H1 (steps#400 through #403), and if these received data are the model type data,these data will be received in a condition to be recognizable as themodel type data (steps #404, #405). If the received data are fineadjustment data, these data will be received in a condition to berecognizable as the fine adjustment data (steps #406, #407). If thereceived data are control setting data, these data will be received in acondition recognizable as the control setting data (steps #408, #409).

Next, the data transmitting process of the traveling control unit H5will be described.

This traveling control unit H5 includes the nonvolatile memory 51 forstoring the control management information for its own, as describedhereinbefore. And, to this nonvolatile memory 51, the same contents willbe written and stored in parallel with the writing to the nonvolatilememory 50 provided in the main control unit HI. Further, the ROM 52 isalso provided for writing and storing therein the alternative controlmanagement information.

This traveling control unit H5, as shown in FIG. 18, upon initiation ofthe control with power supply, executes the same processes as theprocesses by the other storage object control units, aside from theupdating process to the nonvolatile memory 51 (steps #400 through #409).As for the same processes, explanation thereof will be omitted. And, thedifferent processes alone will be described next.

If the control management information (fine adjustment data) transmittedfrom the main control unit H1 is different and has changed from the datastored in the nonvolatile memory 51 and also if this control managementinformation is within the predetermined permissible range, thus notbeing any abnormal value, this obtained data will be written into thenonvolatile memory 51 for updating its contents (steps #407 a, #407 b,#407 c). That is to say, if the control management information (fineadjustment data) transmitted from the main control unit H1 is same as ornot changed from the currently stored data; or if the informationexceeds the permissible range, thus being apparently abnormal, noupdating process will be effected.

By not effecting any updating process in the case of no data change, itis possible to prevent reduction in the usable life of the nonvolatilememory 51 by unnecessary rewriting.

The traveling control unit H5, as the specified storage object controlunit, is configured not to effect any updating process to itsnonvolatile memory 51 if the control management information for its owncannot be received from the main control unit H1, or if the controlmanagement information, even received, exceeds in its value, thepermissible range, thus being clearly abnormal.

Incidentally, in case no control management information has beenreceived from the main control unit H1 or the received controlmanagement information exceeds the permissible range, thus being clearlyabnormal, the data stored in the ROM 52 will be set as the controlmanagement information (steps #23, #24, #25) and the controlled objectassigned thereto (e.g. the hydraulic control section 43) will becontrolled with using these data.

And, as described above, with this combine, the traveling control unitH5 and the engine control unit H7 are capable of effectively controllingthe controlled object assigned thereto independently, even in the eventof absence of communication of the control management information fromthe main control unit H1. So, even when a communication trouble hasoccurred in the field, it is possible to cause the vehicle to travel outof the field to a safe place such as an inter-field path of the field,suitable for repair operation.

Modified Embodiments

Next, modified embodiments will be described.

-   (1) In the foregoing embodiment, the information management control    unit executes the control management information distributing    process for the period after activation with power supply to the    lapse of the management setting period; and each storage object    control unit executes the control management information obtaining    process for the period after activation with power supply to the    lapse of the management setting period. Instead of this    construction, a further construction is possible. In this case, the    information management control unit continues execution of the    control management information obtaining process as long as a    request from the storage object control unit is present, so that the    control management information obtaining process will be effected    until each one of the storage object control unit has received the    information reliably.-   (2) In the foregoing embodiment, when the information management    control unit is transmitting the plurality of kinds of control    management information according to the predetermined sequence, if    there arises a condition of none of the plurality of storage object    control units transmitting the requesting information requesting    that kind of control management information, the subsequent sequence    kind of control management information is transmitted. Instead of    this construction, a further construction is possible. In this case,    all of the plurality of kinds of control management information are    communicated in a butch. In this way, the method of communication    may vary in many ways.-   (3) In the foregoing embodiment, the specified storage object    control unit includes a ROM for storing alternative control    management information. However, the construction without such ROM    is also possible.-   (4) In the foregoing embodiment, the specified storage object    control unit is provided with a nonvolatile memory for the    particular control unit and a ROM. Instead, the specified storage    object control unit may be provided with only the nonvolatile memory    or only the ROM.-   (5) In the foregoing embodiment, as the control management data, the    machine model type data, fine adjustment data and control setting    data are stored. Instead, only one or two of these may be stored.    Or, any other kind of data than such data may be stored.-   (6) In the foregoing embodiment, as specific examples of the storage    object control units, the machine control unit H2, the posture    control unit H3, the threshing control unit H4, the traveling    control unit H5 and the bundling control unit H6 were cited.    However, the present invention is applicable also to a control    system not having one or some of these or a construction having    other kinds of control units.-   (7) In the foregoing embodiment, the combine was described as an    example of the working machine. The invention may be any other kind    of working machine than a combine and the invention is not limited    to work vehicles, but may be applicable also to any stationary    working machine.

[Similar Control System]

Next, an engine control system similar to the control system of theinvention will be described with reference to the accompanying drawings.This control system controls an engine E according to workingcharacteristics of an implement 103 driven by the engine E.

As a conventional engine control system for a working machine, there isknown a system wherein a memory of an engine control unit stores thereinfuel supply amount setting data, and also engine control instructionsetting data for control characteristics corresponding to workingcharacteristics of the implement, so that the engine control unitcalculates an instruction engine rotational speed and an instructionengine torque based on the engine control instruction setting data, andthe engine control unit controls a fuel supply amount of an engine fuelsupplying device, based on these instruction information and fuel supplyamount setting data.

With this system, since the engine control instruction setting data arestored in the memory of the engine control unit, the general versatilityof the engine control unit is low. Namely, since the engine controlinstruction setting data are stored in the memory of the engine controlunit, due to the limit of the storage capacity of the memory, thisengine control unit can store engine control instruction setting datadedicated to only one kind or limited kinds of implement(s). For thisreason, the engine control unit cannot be used as an engine control unitfor driving other kinds of implements, so the general versatility of theengine control unit is low. On the other hand, with an engine controlsystem to be described next, the general versatility of the enginecontrol unit can be enhanced.

An embodiment of the present invention will be described with referenceto the accompanying drawings. FIGS. 19 through 21 are views illustratingan engine control system for a working machine according to oneembodiment of the present invention. In this embodiment, there will bedescribed an engine control system for an agricultural tractor pulling arotary plowing implement.

As shown in FIG. 19, this engine control system is incorporated in atractor including a traveling vehicle body 107 mounting a diesel engineE and a transmission case 108 thereon. The diesel engine E includes anengine fuel supplying device 105. This engine fuel supplying device 105is a common rail type fuel injection device 109. Rearwardly of thetransmission case 108, an implement 103 is provided. This implement 103is a rotary plow implement 110. This rotary plow implement 110 isconnected via a link mechanism 111 to the traveling vehicle body 107 andpulled by this traveling vehicle body 107 and lifted up/down by drive ofa lift operation actuator 123. Power of the engine E is transmitted viahe transmission case 108 to rear wheels 113 and the rotary plowimplement 110. Numeral 114 in FIG. 19 denotes front wheels. With thisengine control system for an agricultural tractor, the engine E iscontrolled according to the characteristics of the implement 103 drivenby the engine E.

The construction of the rotary plow implement is as under.

As shown in FIG. 19, the rotary plow implement 110 includes a plowingsection 115. The plowing section 115 includes a transmission case 116disposed on one lateral side thereof; a pawl shaft 117 mounted betweenthe transmission case 116 and a side frame (not shown) on the otherlateral side; and a plowing pawl 118 mounted on the pawl shaft 117. Theplowing section 115 is covered with a main cover 119 from the upper sidethereof and covered with a rear cover 120 from the rear side thereof.The rear cover 120 is pivotally attached to the main cover 119 via apivot portion 121. The rear cover 120 is placed on the ground surface.To the pivot portion 121 of the rear cover 120, there is attached actualplowing depth detecting means 122 for detecting a pivot angle of therear cover 120.

The construction of the lift operating means of the rotary plow machineis as under.

As shown in FIG. 19, upwardly of the transmission case 108, there isdisposed a lift operating actuator 123; and to a lift arm 124 of thislift operating actuator 123, a lower link 126 is operably connected viaa lift rod 125. In association with a pivotal movement of the lift arm124, the rotary plow implement 110 is lifted up/down. To the liftoperating actuator 123, there is attached an actual lift position sensor127 for detecting the pivot angle of the lift arm 127.

The control of the lift operating actuator is as under.

As shown in FIG. 19, the lift operating actuator 123 for lifting up/downthe rotary plow implement 110 is controlled by a separate control unitHa separate from the engine control unit He. To the separate controlunit Ha, there are connected forcible lift operating means 128, targetplowing depth setting means 129, the actual plowing depth detectingmeans 122 and the lift operating actuator 123. A memory 151 of theseparate control unit Ha stores work data d1 and these work data d1include a plurality of implement data including rotary implement data.In operation, when a target plowing depth is set by the target plowingdepth setting means 129 and a forcible lowering operation is effectedmanually by the forcible lift operating means 128, the separate controlunit Ha executes a feedback control for causing the actual plowing depthto automatically approach the target plowing depth by operating the liftoperating actuator 123 based on the rotary plow implement data in thework data d1, thereby to lower the rotary implement 110 to a targetlowered position. When a forcible elevating operation is effected bymanual operation of the forcible lift operating means 128, the separatecontrol unit Ha controls the lift operating actuator 123 to elevate therotary plow implement 110 to a non-ground contacting position.

In case the implement 103 is a plow implement or a rotary harrowimplement, the separate control unit Ha controls operations of theimplement 103, based on the plow implement data or rotary harrowimplement data.

The construction of the common rail type fuel injection device is asunder.

This common rail fuel injection device 109 includes a fuel supply pump130, a common rail 131 and a fuel injector 132. In operation, the fuelsupply pump 130 supplies fuel in the fuel tank 132 to the common rail131, and the fuel is accumulated in the common rail 131 and the fuelinjector 132 injects this fuel into a combustion chamber (not shown).

The control construction of the common rail fuel injection device is asunder.

Fuel supply to the common rail fuel injection device 109 is controlledby the engine control unit He.

As shown in FIG. 19, to this engine control unit He, there are connectedaccelerator position detecting means 133, actual engine rotational speeddetecting means 134, crank angle discriminating means 135, cylinderdiscriminating means 136, an injection control valve 137 of the fuelinjector 132 as well as actual rail pressure detecting means 138, and adelivery rate control valve 139 of the fuel supply pump 130.

The construction of the engine control system is as under.

The engine control unit He and the separate control unit Ha separatefrom the engine control unit He are interconnected via a datacommunication network TU. This data communication network TU is a CANcommunication bus. The CAN communication bus is a data communicationnetwork for effecting data communication by the CAN (control areanetwork) protocol. The control unit means an electronic control unit.

The engine control unit He is attached to the engine E and the separatecontrol unit Ha is attached to a portion of the traveling vehicle body107 (so-called machine, or main body) mounting the engine E, differentfrom the position of the engine E. Each control unit He, Ha comprises anassembly mounting on a substrate, a controlling section (centralprocessing unit), an EEPROM (electrically erasable, programmable,read-only memory), a flash memory, a RAM (random access memory), a CANcontroller, an input interface, and an output interface.

As shown in FIG. 20, the flash memory of the engine control unit He,i.e. a memory 150, stores fuel supply amount setting data D31. This fuelsupply amount data D31 is map data for calculating a target fuel supplyamount: C of the engine fuel supplying device 105, from an instructionengine rotational speed: A to be described later and an instructionengine torque.

This fuel supply amount data D31 can alternatively be calculationformula data for calculating a target fuel supply amount: C of theengine fuel supplying device 105, from an instruction engine rotationalspeed: A and an instruction engine torque.

The flash memory of the separate control unit Ha, i.e. a memory 151,stores engine control instruction setting data d2 of controlcharacteristics according to the working characteristics of theimplement 103. These engine control instruction setting data d2 are mapdata for calculating the instruction engine rotational speed: A and theinstruction engine torque, based on the control characteristicsaccording to the working characteristics of the implement 103, fromaccelerator information and engine load, with these data being matchedwith each other. The engine load can be calculated from the acceleratorposition data and an actual engine rotational speed. The engine load canbe detected also by a strain gauge attached to the crank shaft.

The engine control instruction setting data d2 can alternativelycalculation formula data for calculating the instruction enginerotational speed: A and the instruction engine torque, based on thecontrol characteristics according to the working characteristics of theimplement 103, from accelerator information and engine load.

The engine control instruction setting data d2 includes a plurality ofimplement data including the rotary plow implement data. In thisembodiment, the implement 103 is the rotary plow implement. Therefore,the separate control unit Ha calculates the instruction enginerotational speed: A and the instruction engine torque, based on therotary plow implement data in the engine control instruction settingdata d2.

In case the implement 103 is a plow implement or a rotary harrowimplement, the separate control unit Ha will calculates the instructionengine rotational speed: A and the instruction engine torque, based onthe plow implement data or rotary harrow implement data in the enginecontrol instruction setting data d2.

The control characteristics according to the working characteristics ofthe implement 103 means e.g. control characteristics for obtaining ahigh torque over a wide range of engine rotational speed to restrictoccurrence of engine stop in the case of a work of large load variation,or for reducing rotational speed variation due to load variation inorder to improve working efficiency in the case of a work of small loadvariation, or for reducing the engine rotational speed prior toengagement of a power transmission clutch between the engine and theimplement, in order to lessens the engagement shock, etc.

The procedure of controlling of the fuel supply amount of the commonrail fuel injection device is as under.

When the engine control unit He transmits accelerator positioninformation and actual engine rotational speed information to theseparate control unit Ha, based on these information and the rotary plowimplement data in the engine control instruction setting data d2, theseparate control unit Ha calculates the instruction engine rotationalspeed: A and the instruction engine torque; and the separate controlunit Ha transmits these instruction information to the engine controlunit He.

Alternatively, the engine control unit He retrieves the engine controlinstruction setting data d2, and the engine control unit He maycalculate the instruction engine rotational speed: A and the instructionengine torque, based upon the accelerator position information, theactual engine rotational speed information and the rotary plow implementdata in the engine control instruction setting data d2.

And, the engine control unit He calculates a target fuel supply amount:C of the engine fuel supplying device 105, based on the aboveinstruction information and the fuel supply amount setting data D31; andbased on this target fuel supply amount: C, the engine control unit Hecalculates a fuel supply amount of the engine fuel supplying device 105.

The control of the fuel supply amount is effected by adjusting the valveopening period of the injection control valve 137 of the fuel injector132, thus adjusting the fuel injection period.

The data stored in the memory of the engine control unit are as under.The memory 150 of the engine control unit He stores basic performancedata D1 and fuel supply limit amount setting data D2. The basicperformance data D1 includes fuel supply setting data D3 and enginerotational speed managing data D4. The fuel supply setting data D3includes fuel supply amount setting data, fuel supply timing settingdata and common rail pressure setting data. These data are map data.But, these can be calculation formula data also. The engine rotationalspeed managing data D4 includes a zero-load minimal rotational speed: B1and a zero-load maximal rotational speed: B2.

The control of the engine control section based upon the above-describeddata is as under.

The engine control unit He controls the fuel supply timing of the enginefuel supplying device 105, based on the instruction information and thefuel supply timing setting data, and controls the common rail pressure,based on the instruction information and the common rail pressuresetting data. Controlling of the fuel supply timing is effected bycontrolling the opening timing of the injection control valve 137 of thefuel injector 132, and controlling of the common rail pressure iseffected by controlling the delivery rate control valve 139 of the fuelsupply pump 130.

The procedure of the control operation of the fuel supply amount by theengine control unit is as under.

As shown in FIG. 21, at step (S1), the process determines whether theinstruction engine rotational speed: A is within the normal rotationalspeed range: B or not. If YES, then, at step (S2), based on thisinstruction engine rotational speed: A, the instruction engine torqueand the fuel supply amount setting data D31, the target fuel supplyamount: C for the engine fuel supplying device 105 is calculated. And,at step (S3), based on the instruction engine rotational speed: A andthe fuel supply limit amount setting data D2, the fuel supply limitabout: D of the engine fuel supplying device 105 is calculated. And, atstep (S4), the process determines whether the target fuel supply amount:C is below the fuel supply limit amount D or not. If YES, at step (S5),based on the target fuel supply amount: C, controlling of the fuelsupply amount of the engine fuel supplying device 105 is effected. IfNO, then, at step (S6), control is effected for limiting the fuel supplyamount of the engine fuel supplying device 105 to the fuel supply limitamount: D.

If NO in the determination at step (S1), then, at step (S7), the processdetermines whether the engine rotational speed instruction value: A isthe zero-load minimal rotational speed: B1 or not. If YES, then, at step(S8), this zero-load minimal rotational speed: B1 is set as theinstruction engine rotational speed: A and then, the process effects thecontrolling of the fuel supply amount of the engine fuel supplyingdevice 105 at steps (S2) through (S6). If NO in the determination atstep (S′, at step (S9), the zero-load maximal rotational speed: B2 isset as the instruction engine rotational speed: A, and then, the processeffects the controlling of the fuel supply amount of the engine fuelsupplying device 105 at steps (S2) through (S6).

Thus, the technical features of the above-described engine controlsystem will be as under:-

(Feature 1)

As shown in FIG. 19, the engine E is controlled according to the workingcharacteristics of the implement 103. In the engine control system for aworking machine, the engine control unit He and the separate controlunit Ha separate from this engine control unit He are interconnected viathe data communication network TU. As shown in FIG. 20, the memory 150of the engine control unit He stores the fuel supply amount setting dataD31, and the memory 151 of the separate control unit Ha stores theengine control instruction setting data d2 of the controlcharacteristics according to the working characteristics of theimplement 103. The separate control unit Ha or the engine control unitHe calculates the instruction engine rotational speed: A and theinstruction engine torque, based upon the engine control instructionsetting data d2. And, as shown in FIG. 21, the engine control unit Hecalculates the target fuel supply amount: C of the engine fuel supplyingdevice 105, based on these instruction information and the fuel supplyamount setting data D31, and the engine control unit He controls thefuel supply amount of the engine fuel supplying device 105, based onthis target fuel supply amount: C.

(Effect of Feature 1)

The general versatility of the engine control unit can be enhanced. Thatis, as shown in FIG. 20, since the memory 151 of the separate controlunit is caused to store the engine control instruction setting data d2according to the working characteristics of the implement 103, there isno need to cause the memory 150 of the engine control unit He to storethe engine control instruction setting data d2. So, it is possible tomanufacture an engine control unit He not limited to the kind of theimplement 103, so that the general versatility of the engine controlunit can be enhanced.

(Feature 2)

The memory 150 of the engine control unit He stores the fuel supplylimit amount setting data D2 and the engine control unit He calculatesthe fuel supply limit amount: D of the engine fuel supplying device 105,based on the instruction engine rotational speed: A and the fuel supplylimit amount setting data D2. And, if the target fuel supply amount: Cis below the fuel supply limit amount: D, the engine control unit. Heeffects the control of the fuel supply amount of the engine fuelsupplying device 105 based on the target fuel supply amount: C. Whereas,if the amount: C is equals to or greater than the fuel supply limitamount: D, the engine control unit He effects the control for limitingthe fuel supply amount of the engine fuel supplying device 105 to thefuel supply limit amount: D. As shown in FIG. 20, the memory 150 of theengine control unit He stores the fuel supply amount limit setting dataD2. And, as shown in FIG. 21, the engine control unit He limits the fuelsupply exceeding the fuel supply limit amount: D based on the fuelsupply limit amount setting data D2. Therefore, regardless of the kindof the implement 103, the management of exhaust gas regulation can bedone all by the engine control unit He.

(Effect of Feature 2)

Regardless of the kind of the implement 103, the management of exhaustgas regulation can be done all by the engine control unit He. The enginecontrol instruction setting data of the separate control unit can befreely set within the range below the fuel supply limit amount based onthe fuel supply limit amount setting data of the engine control unit. Asshown in FIG. 21, if the target fuel supply amount: C is below the fuelsupply limit amount: D, the engine control unit He effects the fuelsupply amount of the engine fuel supplying device 105, based on thetarget fuel supply amount: C. Therefore, the engine control instructionsetting data d2 of the separate control unit Ha, used as the basis forthe calculation of the target fuel supply amount: C, can be freely setwithin the range below the fuel supply limit amount: D based on the fuelsupply limit amount setting data D2 of the engine control unit He.

(Feature 3)

The memory 150 of the engine control unit He stores the zero-loadminimal rotational speed: B1 and the zero-load maximal rotational speed:B2, and when the instruction engine rotational speed: A is within thenormal operation rotational range: B ranging from zero-load minimalrotational speed: B 1 to the zero-load maximal rotational speed: B2, theengine control unit He effects the control of the fuel supply amount ofthe engine fuel supplying device 105 based on this instruction enginerotational speed: A.

Whereas, if the instruction engine rotational speed: A is below thezero-load minimal rotational speed: B 1, the engine control unit Heeffects the control of the fuel supply amount of the engine fuelsupplying device 105 with setting the zero-load minimal rotationalspeed:SI as the instruction engine rotational speed: A.

Whereas, if the instruction engine rotational speed: A exceeds thezero-load maximal rotational speed: B2, the engine control unit Heeffects the control of the fuel supply amount of the engine fuelsupplying device 105 with setting the zero-load maximal rotationalspeed:B2 as the instruction engine rotational speed: A.

(Effect of Feature 3)

The engine control unit can manage the principal basic performances ofthe engine. As shown in FIG. 20, the memory 150 of the engine controlunit He stores the zero-load minimal rotational speed: B1 and thezero-load maximal rotational speed: B2, and based on these, the enginecontrol unit He effects the upper/lower limit rotational speedmanagement of the normal operational rotational speed range: B.Therefore, the engine control unit He can manage the principal basicperformances of the engine.

The above-described engine control system is applicable not only as theengine control system for a tractor having a vehicle body to which arotary plow implement is connected to be pulled thereby, but also anengine control system for an agricultural tractor connecting and pullingother kinds of implements (plow implement, a rotary harrow implement,etc.), an engine control system for an agricultural implement such as acombine having a harvester and a thresher mounted on a vehicle body, anengine control system for a construction implement such as a backhoe,having a bucket implement connected to the vehicle body, an enginecontrol system for an engine-driven electricity generator having agenerator mounted on a machine body, etc. The engine fuel supplyingdevice 105 is not limited to the common rail type fuel injection device109, but can be an electronic governor for controlling a fuel injectionpump and its fuel amount adjustment rack position. The datacommunication network is not limited to the CAN communication bus, butcan be any other data communication network.

1. A control system for a working machine comprising: a plurality ofcontrol units disposed in distribution to be capable of communicatingwith each other via a data communication network, each one of theplurality of control units controlling a controlled object assignedthereto, based upon input information inputted by information inputtingmeans included in this unit, control information communicated from afurther control unit, and control management information; wherein saidplurality of control units are composed of an information managementcontrol unit and storage object control units separate from theinformation management control unit, the information management controlunit having a writable nonvolatile memory for storing the controlmanagement information of the storage object control units as well asthe control management information of this the information managementcontrol unit; upon activation by power supply thereto, said informationmanagement control unit executes a control management informationdistributing process for transmitting the control management informationstored in the memory to said storage object control units via the datacommunication network; and upon activation by power supply thereto, eachone of said storage object control units executes a control managementinformation obtaining process for receiving the control managementinformation for its own transmitted from said information managementcontrol unit via said data communication network.
 2. The control systemfor a working machine according to claim 1, wherein said informationmanagement control unit executes said control management informationdistributing process until lapse of a predetermined management settingperiod after the activation with power supply, and after the lapse ofsaid management setting period, said information management control unitexecutes a control information communicating process fortransmitting/receiving said control information; and each one of saidstorage object control units executes said control managementinformation obtaining process until lapse of the predeterminedmanagement setting period after the activation with power supply, andafter the lapse of said management setting period, said storage objectcontrol units executes a control information communicating process fortransmitting/receiving said control information.
 3. The control systemfor a working machine according to claim 2, wherein said controlmanagement information includes a plurality of kinds of controlmanagement information; in said control management information obtainingprocess, said each storage object control unit transmits a plurality ofkinds of request information according to a predetermined sequence, saidplurality of kinds of request information requesting said plurality ofkinds of control management information respectively; and in saidcontrol management information distributing process, when saidinformation management control unit is transmitting said plurality ofkinds of control management information according to the predeterminedsequence, if none of the plurality of storage object control units istransmitting any request information requesting any one of the pluralitykinds of control management information, said information managementcontrol unit transmits the kind of control management information in thesubsequent order in the predetermined sequence.
 4. The control systemfor a working machine according to claim 3, wherein if each one of thestorage object control units does not receive the requested kind ofcontrol management information in the control management informationobtaining process, the storage object control unit transmits repeatedlythe request information corresponding to that kind of control managementinformation upon lapse of a predetermined unit period.
 5. The controlsystem for a working machine according to claim 2, wherein the storageobject control unit includes a ROM (read-only-memory) for storingalternative control management information; and if the storage objectcontrol unit fails to receive the control management information for itsown to be transmitted from the information management control unit evenafter the lapse of said management setting period, the storage objectcontrol unit controls the controlled object assigned thereto, based onthe alternative control management information stored in said ROM. 6.The control system for a working machine according to claim 2, wherein aspecified storage object control unit among the storage object controlunits includes a writable nonvolatile memory for storing the controlmanagement information for its own; and said specified storage objectcontrol unit stores in said nonvolatile memory the control managementinformation for its own transmitted by said control managementinformation obtaining process; and if the control management informationfor its own to be transmitted from the information management controlunit is not received even after the lapse of said management settingperiod, the controlled object assigned thereto is controlled based oncontrol management information stored in said nonvolatile memory.
 7. Thecontrol system for a working machine according to claim 6, wherein saidspecified storage object control unit includes a ROM for storingalternative control management information; and when control managementinformation for its own is not stored in the ROM provided in thespecified storage object control unit, if the control managementinformation for its own cannot be received from said informationmanagement control unit even after lapse of said management settingperiod, the controlled object assigned thereto is controlled based onthe alternative control management information stored in said ROM. 8.The control system for a working machine according to claim 1, whereinsaid control management information includes information relating to themodel type of the working machine.
 9. The control system for a workingmachine according to claim 1, wherein said working machine includes anactuator acting as said controlled object capable of moving a controlledbody; and a potentiometer type detecting sensor acting as saidinformation inputting means for detecting an operated position of saidcontrolled body; said storage object control unit controls said actuatorbased on detection information of said detecting sensor, andcommunicates as said control management information, to said informationmanagement control unit, fine adjustment data for adjusting individualdifference in detection value of the detecting sensor when saidcontrolled body is operated to a reference position by said actuator.10. The control system for a working machine according to claim 9,wherein said storage object control unit executes a fine adjustment dataobtaining process for updating said fine adjustment data; and whenupdating fine adjustment data are obtained by this fine adjustment dataobtaining process, these fine adjustment data are communicated to saidinformation management control unit.
 11. The control system for aworking machine according to claim 1, the system further comprises anengine control unit for controlling an engine mounted on a work vehicleas said working machine, said engine control unit being providedseparately from said information management control unit and saidstorage object control unit; said information management control unitcommunicates to said engine control unit as said control information,control switchover instructing information, target rotational speedinformation and accelerator operational amount information; and based onsaid control switchover instructing information communicated from saidinformation management control unit, said engine control unit isswitchable between a state for executing an isochronous control formaintaining an output rotational speed of the engine at a targetrotational speed and a state for executing a droop control for adjustingthe output rotational speed of the engine to a speed corresponding to anaccelerator operational amount.
 12. A control system for an engine (E)of a working machine, for controlling the engine according to workingcharacteristics of the working machine driven by the engine, wherein anengine control unit (He) and a separate control unit separate from saidengine control unit are interconnected via a data communication network;a memory of said engine control unit stores fuel supply amount settingdata and a memory of said separate control unit stores engine controlinstruction setting data of control characteristics according to theworking characteristics of the working machine; said separate controlunit or said engine control unit calculates an instruction enginerotational speed (A) and an instruction engine torque, based upon saidengine control instruction setting data; said engine control unit (He)calculates a target fuel supply amount (C) of an engine fuel supplyingdevice based on said instruction information and said fuel supply amountsetting data, and said engine control unit controls a fuel supply amountof the engine fuel supplying device, based on said target fuel supplyamount (C).
 13. The control system for an engine according to claim 12,wherein the memory of said engine control unit stores fuel supply limitamount data; said engine control unit calculates a fuel supply limitamount (D) of the engine fuel supplying device based on the instructionengine rotational speed (A) and said fuel supply limit amount settingdata; when said target fuel supply amount (C) is below said fuel supplylimit amount (D), said engine control unit controls the fuel supplyamount of the engine fuel supplying device based on said target fuelsupply amount (C); and when said target fuel supply amount (C) equals toor exceeds said fuel supply limit amount (D), said engine control uniteffects control for limiting the fuel supply amount of the engine fuelsupplying device to said fuel supply limit amount (D).
 14. The controlsystem for an engine according to claim 12, wherein the memory of theengine control unit stores a zero-load minimal rotational speed (B1) anda zero-load maximal rotational speed (B2); when said instruction enginerotational speed (A) is within a normal operation rotational speed rangeranging from said zero-load minimal rotational speed (B1) to saidzero-load maximal rotational speed (B2), said engine control unitcontrols the fuel supply amount of the engine fuel supplying devicebased on said instruction engine rotational speed (A); when saidinstruction engine rotational speed (A) is below said zero-load minimalrotational speed (B1), said engine control unit effects the control ofthe fuel supply mount of the engine fuel supplying device, with settingthe zero-load minimal rotational speed (B1) as the instruction enginerotational speed (A); and when said instruction engine rotational speed(A) exceeds said zero-load maximal rotational speed (B2), said enginecontrol unit effects the control of the fuel supply mount of the enginefuel supplying device, with setting the zero-load maximal rotationalspeed (B2) as the instruction engine rotational speed (A).